Strategic voting

Suppose you want to “get the Tories out”. Specifically, you want the Conservative party not to be in government.

To be clear, I'm not saying that you should (or shouldn't) want this. But suppose.

How might you vote to achieve this?

Vote for someone else

At first glance, you might just vote for whichever party or candidate you actually want instead of the Conservatives.

But the voting system for UK general elections is first-past-the-post: there are 650 separate constituencies, each of which returns one MP. That MP is whoever gets more votes than any other individual candidate in that constituency, even if the other candidates put together have more votes.

A party can have more than half of the seats (MPs) without persuading more than half of the voters. Since 1931, no single party has ever won 50% of the vote. Most people voting against the Conservatives isn't enough to get them out of government.

Vote tactically

So perhaps there's another candidate in your constituency who you're willing to vote for, and they have a better chance of winning your constituency. You could vote for them, and if they win that would minimise the number of Conservative (or otherwise undesirable) MPs after the next election.

Tactical voting. Job done.

…Right?

For how long?

The thing about general elections is that there's always the next one.

Perhaps Labour will win a majority at this election, and the next one, and the one after that. Do you think Labour will win every election forevermore? What happens when they eventually don't?

If you only want the Conservatives out of government for the next 5 years, tactical voting can do that. Maybe for the next 10 or 15 years.

Suppose you want to keep the Tories out.

Whose confidence?

For a government to stay on, it has to have the confidence of the House of Commons: at least half of the MPs have to be willing to let it continue.

If you're the prime minister and all those MPs are in your own party, that's much easier: you can promise jobs or threaten deselection. But if you have to persuade members of other parties, those tactics don't apply. You have to actually govern in a way that at least half the MPs support.

Under the current voting system, half the MPs doesn't necessarily mean half of the voters. But it could.

Vote strategically

No single party has won 50% of the vote in a general election since 1931. So if the voting system changes to a proportional representation system, it's unlikely the Conservatives would be able to win a majority of seats any time soon.

But if the voting system stays the way it is, it's likely that in the near future the Conservatives would win a majority of seats.

Voting for a party that supports keeping the first-past-the-post voting system is voting for this future.

If you want to keep the Tories out, you can vote strategically for proportional representation.